ADC Snap

Tetracam's Ultra-Fast 90 Gram

Multi-spectral  Imaging System with an Electronic Global Snap Shutter

Overview 

Sensors and Filters

Image Memory

PixelWrench2

Spectral Response

Ground Resolution and Field of View 

System Controls and Connections

Camera Triggering

System Contents

System Options

System Availability

System Features and Specifications

Additional Reference Information

Firmware Updates

 

        

Macaw ADC ADC Lite ADC Micro ADC Snap -MCA RGB+3 Single Band Thermal IR

    

    Click on the Appropriate Icon Above to View Detailed Notes

    on that System.  Scroll down to View Notes on the ADC Snap.

 

 


 

Overview

The ADC Snap and its accompanying software, PixelWrench2, are ideally suited for high-speed capture of multi-spectral images of crops, forests and other eco-systems.  

Featuring 16 GB standard storage, fast parallel processing, ultra-low power consumption, and simple menu-organized configuration and control, the ADC Snap captures visible light wavelengths longer than 520 nm and near-infrared wavelengths up to 920 nm. 

The ADC Snap's exposure time is so fast that engineers in our labs use this camera to capture stop-action photos of fan blades on their desks. These stop action cameras operate at speeds comparable to industrial machine vision cameras.

Three filters atop the sensor limit the radiation that enters it to bands of green, red and near-infrared radiation equivalent to Landsat Thematic Mapper bands TM2, TM3 and TM4.  These bands are the basis for the standard "false color" composite images that have become associated with multi-spectral imagery.  They provide excellent early warning signs of plant stress and their use as indicators of other specific plant and soil conditions has been documented by scientists for decades.

The ADC Snap is housed in the same package as the ADC Micro. It has the same weight, power consumption and interface connections as the ADC Micro (see detailed specifications below). 


Sensors and Filters

The ADC Snap's principal difference from the ADC Micro is that it uses a 1.3 MPel electronic global snap sensor that creates images consisting of 1280 x 1024 pixels.

Rather than using a 'Rolling Shutter" sensor like ADC Micro systems than scan each image from top to bottom, Micro-MCA Snap system sensors expose the entire image at the same instant in time. This allows ADC Snap images to be captured free of motion blur and other distortions. The ADC Snap camera is ideal for use with fast or low-flying UAVs, especially fixed wing aircraft susceptible to pitch, roll or yawing problems.  

 

Image Memory

The ADC Snap's 16 GB micro SD memory card is easily accessible by the user.  Images are stored along with metadata such as GPS coordinates and/or attitude information (pitch, roll and yaw) that is sent to the system through the ADC Snap's serial interface (see I/O connections described below).  Metadata helps users establish the ground location of each image.  After missions are completed, users remove the Micro SD memory from the camera and transfer its contents to a host computer equipped with PixelWrench2, the software included with all Tetracam systems.

 

PixelWrench2

PixelWrench2 provides color processing of Tetracam RAW and DCM files, complex batch processing tools, a comprehensive suite of image editing tools and the ability to extract various vegetation indices such as NDVI from the captured images. 

In addition to indicating plant stress, vegetation indices such as NDVI enable users to deduce information such as biomass, chlorophyll concentration in leaves, plant productivity and fractional vegetation cover as well as predict crop yield.  Refer to  System Application Notes for descriptions of example applications.

 

On the underside of the camera, the ADC Snap possesses a high-quality 8.43 mm lens.  The lens focuses the light that enters the camera on to the system's multi-spectral Snap Shutter image sensor. 


 

 

 

 

   

ADC Snap Sensor

Spectral Response

 

The graph above shows the response of the sensor to different bands of light through the red, green and blue filters. A blue absorbing glass filter is used to eliminate the blue sensitivity, and the blue pixels in the sensor are used to measure NIR. The image is then processed in PixelWrench2 to subtract the measured NIR from the blue and red bands to produce the final NIR/red/green image.

 


 

ADC Snap (with 8.43 mm Lens)

Ground Resolution & FOV Examples

The ADC Snap enables users to gather information about vegetation at wavelengths traditionally monitored by satellites.  Only, flying in manned or unmanned aircraft, data gathered by the ADC Snap is captured at times completely determined by the user, independent of satellite latency, un-obscured by cloud cover and in images that show considerably higher detail than images captured from space (i.e., with resolutions measured in millimeters per pixel rather than meters per pixel).  

The ADC Snap's field of view (FOV) is laid out in a 4:3 format.  The horizontal angle of view for the system is 37.67 degrees.  The vertical angle of view is 28.75 degrees. When carried in a manned or unmanned aircraft, the field of view increases as the above ground level (AGL) altitude increases.  

As the AGL increases, the camera's ability to resolve individual details on the ground decreases.   With its standard 8.43 mm lens, when flown at altitude of 400 feet (122 meters) above ground level, this camera creates an image large enough to capture an area measuring 95 meters wide by 71 meters high at a resolution of less than three inches (72.36 mm) per pixel in a single shot. 

Below is a table that shows the ground resolution and field of view for images gathered at various altitudes above ground.  PixelWrench2 contains an FOV Optical Calculator that enables determination of the system's field of view and ground resolution for any user-specified altitude.  For operation in the field, this utility is also available as a free app that runs on Android cell phones.  For information on this app, click here.

 
Sensor & Lens Parameters

Object Distance

(Altitude Above Ground Level in meters)

Ground Resolution

in mm per pixel

FOV

(width x height)

in meters

The values shown at right were derived from the FOV (Field of View) Optical Calculator contained in Tetracam's PixelWrench2 software (included with this camera) using the current values for this camera shown below: 

Sensor Dimensions (mm):  6.59 x 4.9

Pixel Size (in microns): 5.0

Camera Lens Focal Length (mm):  8.43

122 m (~ 400 ft)

72.36

95.4 x 70.9

213.4 m (~ 700 ft)

126.54

166.782 x 124.517

365.8 m (~ 1200 ft)

216.91

285.89 x 213.441

915 m (~ 3000 ft)

542.58

715.115 x 533.895

Note: In order to view a larger composite image of an area of interest, users may purchase third party software that stitches multi-spectral images of adjacent areas captured by a Tetracam system together into a larger image mosaic.  For information on such software, please send us email.


 

System Controls, Indicators and Connections

 

ADC Snap Interconnection Pins

The ADC Snap contains labeled interconnection pins at the top of the front panel.  These connect to the Un-terminated System Integration Cable and to the ADC Snap Test and Control Box Assembly and Cable, both of which are supplied with the system.  The Un-terminated System Integration Cable may be used to connect the camera to external devices in a manned or unmanned aircraft such as an autopilot, GPS or video transmitter.  Information on the ADC Snap's flat Multi-IO connector and the cables that are available from Tetracam to connect to it are shown on our web site here.

   

Pin 15 GND: System Ground

Pin 14 +3VOUT: +3.3 Volts accessory power

Pin 13 VIDGND: Video ground reference

Pin 12 VIDEO:  NTSC or PAL Video signal out. The video format is controlled by the SETTINGS.TXT file. Video coax cables should be used for connecting video devices.

Pin 11 SPARE: Unused input.

Pin 10 GRNLED: READY

Pin 9 REDLED: BUSY

Pin 8 RS232RX: (GPS IN)

Pin 7 RS232TX: Serial Output

Pin 6 SYNC: GPS Sync event input pin

Pin 5 SHUTTER: Ground to take a picture

Pin 4 DOWN: Zoom live view to 1:1

Pin 3 UP: Un-implemented Menu Control Pin

Pin 2 SELECT: Un-implemented Menu Control Pin

Pin 1 +VDC: +5 Volt to +15 Volt input power pin

 

 




 

  ADC Snap Controls & Indicators

User control of the ADC Snap is accomplished through hierarchical system menus such as the one shown below. The system menus present users with a series of configuration choices.  Scrolling through and selecting these configures the camera.  

The system menus are visible via a video display (supplied by the user) interconnected by the ADC Snap Test and Control Box Assembly described below. 

The Menus may be navigated by means of buttons visible on the top of the camera.  Viewed left to right, these allow you to scroll up, down or choose a specific menu selection.  An additional button on the far right side of the panel allows you take a picture. 

To the left of these buttons, the ADC Snap contains a USB connector.  System menus may be accessed via the system software (PixelWrench2) running on a Windows computer connected to the ADC through its USB interface.

Check out the ADC Snap User Manual for precise descriptions of the system menus.

The ADC Snap contains a Busy indicator on the top of the camera.  The indicator is lit red when the camera is busy processing a captured image.  The indicator is lit green when the camera is ready to capture a new image.

The system's Micro SD Card is inserted at the bottom of the camera's face panel. The card is removed from the ADC Snap in order to transfer images to a computer for processing. This card may be inserted directly into a computer that will accept such cards or it may be connected to a computer through a Micro SD/USB adapter provided with the camera.

ADC Snap Cable

The cable provided with the ADC Micro is an un-terminated System Integration Cable.  This has the same pin-outs as are present on the ADC Micro edge connector.  The un-terminated cable enables the user to connect the camera to other equipment in a manned or unmanned aircraft (e.g., autopilot, GPS system or video transmitter).

Test and Control Box Assembly

The ADC Snap Test and Control Box Assembly (shown at right) is included with each ADC Snap system. This contains buttons that enable the user to manually scroll up and down through system menus, pick a selection or take a picture. Via its 15-Pin Multi-I/O connector, this box also may be used to interconnect the camera with the RS232 transmit and receive lines of an optional GPS receiver in order to determine GPS coordinates at image capture time. The box may also be used to interconnect the camera's NTSC or PAL video signal output to an external monitor.

 


 

Camera Triggering Options

The ADC Snap may be triggered by various means depending upon the user's preference.   These include:

  • On-Camera Shutter Release: The ADC Snap possesses a Take Pic button on the camera itself which when pressed triggers the camera 

  • Auto-Timer: The ADC Snap may be configured to capture images continuously at intervals specified by the user via the camera's system menus.   Press the Shutter Release or trigger the system via one of the methods below to begin continuously capturing images.  Press the Shutter Release or trigger the camera again to stop continuous capture of images.  Always stop continuously capturing images by pressing the On-Camera Shutter Release or via a trigger command prior to powering the system off.  Interruption of power during continuous capture of images may damage the ADC Snap. 

  • Remote Shutter Release: The ADC Snap's included Controller Box enables users to manually trigger the camera by pushing a button at the desired moment.

  • External Triggering on UAV: Used on a UAV, UAV circuitry may be patched through its un-terminated System Integration Cable (included with the system) to deliver a low-true TAKE PIC command to the ADC Snap via Pin 5.

  • RS-232 Triggering:  The camera may be commanded to trigger by receiving an <ESC> T command via the RS232 connection on the ADC/MCA Box.  Due to the delays incumbent in a serial interface, the RS232 link is more commonly used to transfer GPS position coordinates to the camera at camera trigger time. When the camera is connected to a GPS receiver via its System Integration Cable, the camera records the coordinates of the location at which each image is captured into its log file upon receiving any camera trigger command.


 

Standard System Contents

 

System Contents Includes:

  • ADC Snap Agricultural Digital Camera

  • CDROM with Installation Software and Documentation

  • Product Manual and Accessory Documentation

  • USB Interconnection Cable

  • 16 GB Micro SD memory card

  • Micro SD to USB Reader/Adapter

  • DC Power Supply with International Adapters

  • White Teflon Calibration Plate (AKA Calibration tag or Software Calibration Tile)

  • Test and control box assembly and Cable

  • Un-terminated System Integration Cable

  • Hardened Plastic Storage and Transport Case

 

Typical Availability:

 

2 to 3 weeks (although faster turnaround times are

often possible). Please contact us for more information regarding configuration options, pricing and availability.

Options Commonly Purchased with this Product: 

 

System Contents:

 
   


 

Summary of ADC Snap System Features and Specifications

 

 

 Specification/Feature

 

 Description/Value

 

 Remarks

 

 

 

System Overview

 

90 gram 1.3 MPel Multi-spectral

R-G-NIR System principally designed for operation aboard unmanned aircraft

 

 

The ADC Snap, ADC Micro and ADC Lite are specifically designed  for operation aboard unmanned aerial vehicles.  The advantage of the ADC Snap is that its faster image capture time optimizes this camera for high-speed flight close to the ground or for use with UAV systems that are prone to yawing, pitching or rolling.

 

 

Multi-spectral Bands

 

3-Fixed Green, Red, NIR (Equivalent to Landsat TM2, TM3, TM4)

 

 

 

 
  Indicators

  The ADC Snap Busy LED is located on the lower right side of the front of the camera.

Red indicates a Busy condition.  Green, a Not Busy condition.  When this indicator is lit green, the camera is ready to capture a new image.

 

 

The ADC Snap Busy LED glows red at the exact beginning of integration of an image into the camera's sensor.  The indicator stays red until the image is saved in memory.  During this time, the camera is not able to capture another image.  When this LED is green, the camera is not busy and another image may be captured.

 

 
Memory 16 GB Micro SD Memory Card provided standard with equipment In order to run at the fastest image cycle time we recommend use of 16GB Sandisk Extreme Plus or Extreme Pro Class 10/UHS-1 Micro SD memory cards.  Camera cycle time with these cards should be less than 1 second in the raw 10 bit RWS10 format. 

 

 

Default Ports

 

Video (NTSC or Pal), USB, RS232 Serial, Remote Shutter (External Trigger)

 

 

 

 
    Video (NTSC or PAL)   Used to view system menus for system configuration or to act as camera viewfinder.  The video format and viewing mode (system menus or viewfinder) are user selectable.

 

  Video is accessible through the ADC Snap's Interconnection Pins 12 and 13.  These pins may be connected to the Test and Control Box Assembly which contains an RCA video connector or they can be wired to a monitor or video transmitter via an included Un-terminated System Integration Cable.  
    USB   USB 2.0 used to connect the camera to a computer for system configuration

 

 

 

The USB 2.0 connection for the camera is located on top of the housing as shown in the illustration below. For reliable USB 2.0 communications, good quality USB 2.0 rated cables should be used that are less than 2 meters in length. The camera uses too much initial power to be supplied directly from the USB cable. It must have an external power supply attached prior to being plugged in for enumeration.

The camera always operates as a USB Disk device when attached to a host. The camera will be recognized by its volume ID TTCDISKS when the Pixelwrench2 GPS Distiller application is started. Files can be dragged and dropped to and from the camera from any personal computer that has USB disk drivers.

 
 
    RS232 Serial   Principally used to connect to devices that stream continuous GP coordinates or other location information in standard NMEA sentences to the camera through its Interconnection Pins 7 and 8.  These pins may be connected to the Test and Control Box Assembly  for connection via a 3.5mm stereo phone plug to an external device or wired directly to the external device via an included Un-terminated System Integration Cable.

 

  By default, the camera serial port is configured 4800, the NMEA 0183 standard configuration.  Serial configuration may be altered via system menus.  GPS coordinates and other data is saved in the camera's image memory as metadata.  This may be extracted by PixelWrench2 or other application software.  The serial port may also be used to control the camera from an external serial interface using simple text commands (see User Manual for details).

 

 
    Remote Shutter   Used as an external trigger to initiate image capture through the ADC Snap's Interconnection Pin 5.    Images are triggered by grounding pin 5.   

 

Power

+ 9.0 VDC to + 14.7 VDC (160 mA); Two watts nominal

 

 

 

 

 

 

 

 

 

 

ADC Snap Sensor

 

 

 

 

 

 

  Range

 

520nm to 920nm

 

520nm to 920nm

 

 

  Size in Pixels

 

1.3 MPel

 

1280 x 1024 pixels

 

 

  Dimensions

 

6.59 mm x 4.9 mm

 

 

 

 

  Pixel Size

 

5.0 microns

 

 

 

 

Optics

 

 

 

 

 

 

  Focal Length

 

8.43 mm fixed lens

 

 

 

 

  Aperture

 

f/3.2

 

 

 

 

 

 

 

 

 

 

 

  Horizontal Angle of View

 

37.67 degrees

 

Consult FOV calculator in PixelWrench2 - See also FOV Android APP

 

 

  Vertical Angle of View

 

28.75 degrees

 

Consult FOV calculator in PixelWrench2 - See also FOV Android APP

 

 

  Default Depth of Field

 

~3 m to infinity

 

Consult FOV calculator in PixelWrench2 - See also FOV Android APP

 

 

Image Exposure time

 

Auto or menu-selectable in ms

 

 

 

 
 

Image Triggering

 

On-Camera Shutter Release, Auto-Timer,  Remote Shutter (External Trigger),  RS232 Serial Trigger

 

     

 

Default Image Dimensions

 

1.3 Megapixel (1280 x 1024 pixels)

 

ADC Snap image size may be adjusted to an alternate image size via system menu selection

 

 
  Default Image Storage Medium

  The ADC Snap stores all images and metadata on a standard 16 GB Micro SD memory card which is inserted into the camera in the Memory Card slot beneath the Busy Indicator.    The Micro SD card may be inserted directly into a computer that will accept such cards or it may be connected to a computer through a Micro SD/USB adapter provided with the camera.

 

 

 

Default Image File Types

 

.RWS   is the snap shutter version of the .RAW files saved be other cameras. After removal of noise and pixel reordering, these are converted to .RAW images.

.DCS  is a snap shutter variant of the .DCM compressed format.

 

 

 

 

The shifting scheme of the sensor and the fact that these sensors are susceptible to high dark current noise require correcting these problems during post-processing on the host computer.  Consequently, the images taken by the ADC Snap camera have different file extensions than those of the rest of the ADC family to enable PixelWrench2 to recognize that special post-processing correction to these images will be necessary.  Once processed, image file formats are translatable via PixelWrench2 into other common image file types such as BMP, JPEG, TIFF, PNG, etc.

Images initially appear as monochrome images.  PixelWrench2's Index Tools enable users to translate monochrome images to false color images and then derive vegetation indices such as NDVI from these.

The RWS files are quite large: 2.6 megabytes for the 10 bit format and 1.3 megabytes for the 8 bit format. Compression (DCS format) cuts the size of the files in half and retains full precision, but takes longer to capture. The DCS compressed continuous mode may be designated as low speed. Besides the smaller file size, another advantage of the DCS format is that the files contain previews which speed up the image access speed using Pixelwrench2.

 

 
  Typical Number of Images Captured Per Mission   Approximately 5000 + images depending upon selected file type (i.e., 10 bit DCM lossless, 8 bit RAW, and 10 bit RAW file types).

 

  Higher numbers of images may be captured per mission by substituting an optional larger Micro SD Card for the 16 GB card included in the camera's standard contents.  

 

Image Capture Interval

(Speed dependent on SD Card Features)

 

Capacity:

(DCS10) Approx.1.8MB per image
(RWS10)2.6MB per image
(RWS8)  1.3 MB per image
 

Rate:       

 

 (DCS10) Capture to end of cycle: ~ 3 sec.

(RWS10) Capture to ready : 1.0 sec.
 

(RWS 8)  Capture to ready : 1.2 sec.

 

 

The highest rate of capture is with the 10 Bit RWS file format, at about one picture per every second, depending on the speed of the micro SD memory card. For users who want more pictures on a card, and do not need precision, the 8 bit RWS format is the next fastest, about 2.5 to 3.5 seconds per picture.

The camera can capture still images at reduced resolution to speed up the camera cycle time. Choose 1280 X 1024 for full resolution shots and 1+ second cycle time. Choose 640 X 512 for half resolution and .5 second cycle time.

 

 

 

Included Software

 

PixelWrench2 is included with each purchase of an ADC Snap

 

PixelWrench2 enables users to convert images captured in Tetracam native file formats to file types commonly used with other software.  The software also enables users to convert the green, red and invisible NIR bands captured by the camera as a monochrome image into blue, green and red respectively for presentation in false color images and, following this, extraction of vegetation indices such as NDVI from these.   See PixelWrench Product Web Page and the Help menu in the software for further details.

 

 

Weight

 

90 g (3.17 ounces)

 

 

 

 

 

Dimensions 

 

 

75 mm x 59 mm x 33 mm

2.97"  x 2.33"  x 1.29"

 

 

 

 

Environmental  

 

Note: the camera will operate outside of the recommended environmental range, however performance may be degraded.

 

 

 

  • Temperature
    0 degrees Celsius to 40 degrees Celsius (32 degrees Fahrenheit to 104 degrees Fahrenheit) 

  • Humidity
    Less than 85% relative humidity, non-condensing    

 

 

 

 

 
 

Additional ADC Snap Reference Information

 
 

Note:  All data shown in the printed reference materials linked below are subject to obsolescence prior to posting of new printed materials.  If discrepancies exists between data shown in these reference materials or between data shown in these materials and data shown on our web site,  please send email to sales@tetracam.com for clarification.

 

ADC Snap Users Manual (pdf format)


ADC Snap CAD Drawings (pdf format)

 

ADC Snap CAD Drawings (IGES format)

 

ADC Snap CAD Drawings (Solidworks format)

 

ADC Snap Latest Firmware Download  (Contact support@tetracam.com)

 

Tetracam Warranty Card


Example ADC Snap Images:

 

Below are links to sample ADC Snap Images (shown in dark blue).  The Color Profile file (cpf) identifies color compensation information for the camera that took these pictures (see PixelWrench2 Help file on the topic of "Matrix").  To view these images, please use PixelWrench2 which can be downloaded from our web site at the following link:

http://www.tetracam.com/PWversion.htm

 snap 240102.cpf (74B)
TTC00039.TIF (2MB)
TTC00040.TIF (2MB)
TTC00041.TIF (2MB)
TTC00042.TIF (1MB)
TTC00043.TIF (2MB)
TTC00045.TIF (2MB)
TTC00046.TIF (2MB)